/*********************************************************************
 * Copyright (C) 2002 Andrew Khan
 * <p>
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * <p>
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * <p>
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 ***************************************************************************/

package jxl.biff.formula;

import jxl.read.biff.BOFRecord;

/**
 * Interface which exposes the methods needed by formulas
 * to access external sheet records
 */
public interface ExternalSheet {
    /**
     * Gets the name of the external sheet specified by the index
     *
     * @param index the external sheet index
     * @return the name of the external sheet
     */
    public String getExternalSheetName(int index);

    /**
     * Gets the index of the first external sheet for the name
     *
     * @param sheetName the name of the external sheet
     * @return the index of the external sheet with the specified name
     */
    public int getExternalSheetIndex(String sheetName);

    /**
     * Gets the index of the first external sheet for the name
     *
     * @param index the external sheet index
     * @return the sheet index of the external sheet index
     */
    public int getExternalSheetIndex(int index);

    /**
     * Gets the index of the last external sheet for the name
     *
     * @param sheetName the name of the external sheet
     * @return the index of the external sheet with the specified name
     */
    public int getLastExternalSheetIndex(String sheetName);

    /**
     * Gets the index of the first external sheet for the name
     *
     * @param index the external sheet index
     * @return the sheet index of the external sheet index
     */
    public int getLastExternalSheetIndex(int index);

    /**
     * Parsing of formulas is only supported for a subset of the available
     * biff version, so we need to test to see if this version is acceptable
     *
     * @return the BOF record
     */
    public BOFRecord getWorkbookBof();
}
